Acid stabilization of meat based foods

ABSTRACT

THE INVENTION RELATES TO THE USE OF CAPROIC, CAPRYLIC AND LEVULINIC ACID COMBINED WITH A SORBIC ACID COMPOUND, AND MIXTURES THEREOF, AS ANTIMYCOTICS TO PRESERVE FOODS CHARACTERIZED BY HIGH DEGREES OF PALATABILITY, NUTRITION AND CALORIC VALUE.

United States Patent US. Cl. 99-159 1 Claim ABSTRACT OF THE DISCLOSUREThe invention relates to the use of caproic, caprylic and levulinic acidcombined with a sorbic acid compound, and mixtures thereof, asantimycotics to preserve foods characterized by high degrees ofpalatability, nutrition and caloric value.

This application is a continuation-in-part of application Ser. No.829,720, filed June 2, 1969, and application Ser. No. 827,030, filed May22, 1969, both entitled Animal Food Products.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to intermediate moisture food products and the productionthereof.

DESCRIPTION OF THE PRIOR ART The concept of intermediate moisture foodproducts, particularly animal foods, is set forth in US. Pat. No.3,202,514; these products usually have a moisture content in excess ofand substantially below 75%. In general, any significant elevation ofthe moisture level of many foods above 10% will increase theirpalatability; however, it leads to microbiological decomposition unlessthe food products are packaged in a hermetically sealed container andcommercially sterilized or maintained in a frozen or refrigerated statethroughout the period of distribution and storage by the consumer.

One method of preventing microbiological decomposition in foods havingmoisture in excess of 10% is by employing the principle of limiting theamount of unbound water capable of supporting microbiological spoilage.This principle is disclosed in US. Pat. No. 3,202,514, and is known asthe Aw, or the ability of the soluble solids in the food to limit theamount of free water available to bacteria, the bacterias inability tosurvive this condition, and the subsequent shelf stability or productstability obtained by virtue of this condition.

Since shelf or product stability is the result of having substantiallytotally inhibited harmful mold growth, as well as bacteriologicalgrowth, it has been necessary to incorporate antimycoti-cs such aspotassium sorbate in intermediate moisture foods to prevent molddevelopment and ultimate shelf instability. However, two objectionableaspects are attendant in the use of potassium sorbate as theantimycotic; namely, its high cost and its tendency to lessen thepalatability, particularly of animal foods to dogs.

SUMMARY OF THE INVENTION It has now been found that caproic acid orcaprylic acid, which occur naturally in some cheeses and soy sauces, butnot in meats, may be employed in non-intermediate moisture andinter-mediate moisture foods, particularly meat or meat-product animalfoods as effectively as similar proportions of potassium sorbate, toprevent mold growth. It has also been found that the proportion of po-Patented July 3, 1973 tassium sorbate required may be reduced iflevulinic acid is combined with the potassium sorbate.

DESCRIPTION OF THE INVENTION According to the invention there isprovided a food composition containing water soluble materials, at leastin part in aqueous solution, in an amount sufiicient to provide anosmotic pressure which inhibits microbiological decomposition, and amold growth inhibitor which is caproic acid, caprylic acid or acombination of levulinic acid and potassium sorbate, which moldinhibitor is present in an amount effective to limit mold growth.

The preferred products are those in which the moisture content isbetween 15 and 30% by weight, and the amount of water soluble solids isat least equal to the weight of moisture. As will be indicated, theinvention is particularly applicable to a food composition which is ananimal food having a matrix of proteinaceous meaty materials permeatedwith the solution of water soluble solids.

The use of these inhibitors of mold growth eliminates: (1) the problemsof the high cost of employing potassium sorbate in proportionssufiicient to totally inhibit mold growth in meat or meat-product animalfoods (0.3% by weight); (2) the reduced palatability to dogs of animalfoods containing 0.3% by weight of potassium sorbate; and it has beenfound that they are just as effective as potassium sorbate alone inpreventing mold growth.

Although the formulations of the invention will be described herein,particularly on animal or pet food varieties, the benefits ofmicroorganic stabilization herein presented will likewise be applicableto conventional human foods and intermediate moisture human foods havinga bacteriostatic or stabilizing quantity of water soluble solutes. Amongthe intermediate moisture human foods which will be so stabilized aresausage-like formulations, liquid preparations such as syrup, simulatedcheeses and egg products, French toast, pancake and waflle products, andthe like. These foods may be aerobically packed in a non-hermeticwrapper such as cellophane, whereupon such packaged products can bestored without refrigeration for periods of 3 to 6 months or longer.

The type of antimycotics permitted in animal foods are few, and thecharacteristics and activities of these materials in moist systems havebeen adequately described in textbooks. However, little information isavailable on the activity of these antimycotics and preservatives insystems of lower moisture, where the reduced water activity has aninhibiting action per se on microorganisms.

The relative weight percent of water soluble solids to moisture contentof the animal food, when initially incorporated into the animal foodduring its manufacture and preparatory to packaging determines theultimate functionality of the solids in providing the requisitebacteriostatic effect. Usually the amount of moisture will range from 15to 30%. The amount of water soluble solids (principally sugar) may bevaried, as may the level of moisture incorporated within the desiredranges. However, in varying these levels the relationship of the watersoluble solids in solution to the water should be controlled so as toafford the desired osmotic pressure. A good rule to observe in thisconnection is to be sure that the water soluble solids available forsolution are at least equal to the weight of moisture present, althoughin some cases it is possible that a lower level of water soluble solidsmight afford some protection against microbiological decompositionprovided an equivalent degree of osmotic pressure is available toprotect the product.

In performing tests to determine the effect of mold growth inhibitors,for instance levulinic acid alone, and in combination with potassiumsorbate, on non-intermediate moisture and intermediate moisture meat andmeat-product animal foods, at system was developed which would maintainmost of the characteristics of reduced water meat and meat productanimal foods and, at the same time, accelerate mold growth to such anextent that useful results could be obtained by inspection for visualgrowth of generic microorganisms such as Aspergilli and Pennicilliawithin weeks.

To judge the degree of inhibition, the tests were carried out at 23 C.and 33 C. The samples were inspected daily and the number of days forvisible mold formation determined. In the eflEectiveness scale,represents no extension of shelf life or extension for less than doublethe control which contained no antimicrobial or antimycotic, 1 is doubleto triple the shelf life, 2 is triple to quadruple the shelf life, 3 isquadruple to tenfold the shelf life, 4 is at least tenfold the shelflife, and 5 signifies complete inhibition or approximately six months atboth storage temperatures.

The following example will more specifically set forth the preferredembodiment of the invention.

EXAMPLE I Meat-product animal food Ingredients: Parts by weight Choppedmeat by-products (tripe, udders,

cheek trimmings, tongue trimmings, gul- -An intimate mixture of theforegoing ingredients was made by first chopping the meat by-productsinto small pieces, which were then heated in combination with tallow to212 F. to effect pasteurization and produce a liquefied slurried meatcomposition. The aforesaid slurry was then finely ground into a more orless pulpy, pumpable, floWable puree consistency. This hot pureed formof slurry was then proportionately blended with the remaining dryingredients of the formulation in a steam jacketed cooker wherein itremained for a period of approximately 1 /2 minutes at an elevatedtemperature of about 200 F., the product being under continuousagitation throughout this cooking phase. This cooked mixture had aplastic, extrudable, shape-retaining consistency. The moisture contentof this composition was 25%. The finely comminuted meat by-products andthe soya flakes had the aqueous phase evenly distributed throughout,thereby assuring a maximum bacteriological protection to the finalproduct.

The pasteurized mixture was immediately cooled by passage through arefrigerated heat exchanger to an ambient temperature.

The samples used in the test are a blend of one-half of a meat-productanimal food and one-half of a 45% sucrose solution; however, withoutpotassium sorbate or any other antimycotic. A sucrose solution is usedbecause the liquid phase of the meat-product animal food is a solution,where most of the solute is sucrose. The sample was divided into partsand antimycotics were mixed thoroughly into each for one minute atmedium speed, and half the paste of each sample was transferred to jarsand stored at room temperature (about 23 C.) and the other half at 33 C.The results of these tests appear in Table I.

TABLE I Degree of Level for Percentage inhibition total in- Antimycotmtested at top level hibition Potassium sorbate 0. 1, 0. 3 6 0. 3Levulinic acid 1. 0 0 Caproic acid 0.1, 0.2 5 0.2 Caprylie acid 0. 1, 0.3 5 0. 3

TABLE II Days of first visible mold growth 23 C. 33 C. .Antimycoticstorage storage None 7 4 Potassium sorbate, 0.1% 15 7 Potassium sorbate,0.3% 70 70 Levulinic acid, 0.1% 32 Potassium sorbate, 0.1% Levulinicacid, 1.0%-- 8 6 Levulinic acid, 0.1%.. 8 6 Caproic acid 0.2%-.-- 70 70Capryllc acid, 0.3% 70 70 Inasmuch as the step of diluting themeat-product animal food in half with 45% sucrose solution results inincreased Aw, any antimycotic which is active under these more stringentconditions of Aw and temperature could be expected to be considerablymore eifective in undiluted meat-product animal foods having a low Aw;and such was the case.

EXAMPLE II Same as Example 1, except that the 45 sucrose solution wasomitted. In this example, the water soluble sugar solids were maintainedbetween 15 to 35% by weight of the composition, and the weight level ofwater soluble solids is at least equal to or greater than that of themoisture of the composition; said moisture weight range being from 15 to30% of the composition.

The intermediate moisture samples employed in Example II had a moisturecontent between 22 to 23.5%. In Table III of Example II, it can readilybe seen that the relationship between the moisture content of theintermediate moisture meat-product animal food employing the variousantimycotics, and the speed of visible contamination could not bedetermined up to 170 days; after which the experiment was terminated.

The results of Example I indicate that the use of caproic and caprylicacids in non-intermediate moisture meat-product animal foods is aseffective as similar proportions of potassium sorbate in preventing moldgrowth.

While the invention discloses and describes the use of caproic andcaprylic acids alone as being just as eifective as potassium sorbate ininhibiting mold growth, it is to be understood that any and allcombinations of caproic acid, caprylic acid and potassium sorbate may beemployed in the invention at levels effective to prevent mold growth.

In Example I, it may be seen that the use of levulinic acid in amountsas high as 1.0% is not effective in totally inhibiting mold growth, andthat 0.3% potassium sorbate must be present to totally inhibit moldgrowth. However, the combination of one-half levulinic acid and one-halfpotassium sorbate is more effective than about twice that of eitheralone in preventing mold growth on diluted or non-intermediate moisturemeat-product animal foods.

While the invention discloses and describes the use of one-halflevulinic acid in combination with one-half potassium sorbate to inhibitmold growth, it is to be understood that any and all combinations oflevulinic acid and potassium sorbate, with or without caproic andcaprylic acid, may be employed in the invention at levels efiective toprevent mold growth.

The claim defining the invention is as follows! 1. A method ofstabilizing moist food compositions comprising a matrix of meat basedmaterials having an aqueous solution of water-soluble solidsincorporated in said matrix mateials, the moisture levels in saidcompositions ranging from about 15 percent to about 30 percent by weightof the composition and the level of water-soluble solids being at leastequal to the weight of moisture in the composition which comprisesincorporating in the composition a mold growth inhibitor selected fromthe group consisting of (1) 0.1 percent levulinic acid and 0.1 percentpotassium sorbate by weight of the composition. (2) 0.3 percent caprylicacid by weight of the composition; (3) 0.2 percent caproic acid byweight of the com- 6 position; and (4) mixtures thereof to prevent moldgrowth.

References Cited UNITED STATES PATENTS 3,564,098 2/ 1971 Erwin et a1.424-317 3,202,514 8/1965 Burgess et al. 99-2 2,831,769 4/1958 Kamlet424-317 3,510,317 5/1970 Fernholz et al. 99-150 2,476,802 7/1949 Bollens99-171 CA 3,275,505 9/ 1966 Herschler 424-317 3,276,881 10/1966 Troller99-139 3,486,909 12/1969 Luck 99-162 3,623,884 11/1971 Haas 99-73,658,548 4/ 1972 Haas 99-2 R NORMAN YUDKOFF, Primary Examiner C. P.RIBANDO, Assistant Examiner US. Cl. X.R. 99-2 R, 224

